function sys=plants(t,x,dt)
sys=zeros(12,1);

lamb1=1.2;lamb2=1.2;lamb3=4;lamb4=1.01;
kd1=0.08;kd2=0.08;kd3=0.03;kd4=1.0;
ksiphi=dt(1);ksith=dt(2);ksifi=dt(3);ksih=dt(4);
alpha1=0.001;alpha2=0.001;alpha3=0.001;alpha4=0.01;
PHI1=0.01;PHI2=0.01;PHI3=0.001;PHI4=0.1;

s1=x(1);ds1=x(2);s2=x(3);ds2=x(4);
s3=x(5);ds3=x(6);s4=x(7);ds4=x(8);
gama1=x(9);gama2=x(10);gama3=x(11);gama4=x(12);

% gama1=max(kd1*9,gama1);
% gama2=max(kd2*9,gama2);
% gama3=max(kd3*7,gama3);
% gama4=max(kd4*22,gama4);

sys(1)=ds1;
sys(2)=-lamb1*s1-gama1*saturate(ds1/PHI1,-1,1)-kd1*ksiphi;
sys(3)=ds2;
sys(4)=-lamb2*s2-gama2*saturate(ds2/PHI2,-1,1)-kd2*ksith;
sys(5)=ds3;
sys(6)=-lamb3*s3-gama3*saturate(ds3/PHI3,-1,1)-kd3*ksifi;
sys(7)=ds4;
sys(8)=-lamb4*s4-gama4*saturate(ds4/PHI4,-1,1)-kd4*ksih;
sys(9)=1/alpha1*abs(ds1);
sys(10)=1/alpha2*abs(ds2);
sys(11)=1/alpha3*abs(ds3);
sys(12)=1/alpha4*abs(ds4);
end